Prevent triggering Clang 12 -Wstring-concatenation warning

Wrap multi-line string literals in parentheses
to prevent a Clang 12 -Wstring-concatenation warning
(activated by -Wall), which caused the build to fail.

Fixes https://github.com/ARMmbed/mbedtls/issues/3586

Signed-off-by: Guido Vranken <guidovranken@gmail.com>
diff --git a/library/md2.c b/library/md2.c
index fdcb630..13cb13f 100644
--- a/library/md2.c
+++ b/library/md2.c
@@ -320,8 +320,8 @@
     { "message digest" },
     { "abcdefghijklmnopqrstuvwxyz" },
     { "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" },
-    { "12345678901234567890123456789012345678901234567890123456789012"
-      "345678901234567890" }
+    { ("12345678901234567890123456789012345678901234567890123456789012"
+      "345678901234567890") }
 };
 
 static const size_t md2_test_strlen[7] =
diff --git a/library/md4.c b/library/md4.c
index 95e893e..7b535c9 100644
--- a/library/md4.c
+++ b/library/md4.c
@@ -444,8 +444,8 @@
     { "message digest" },
     { "abcdefghijklmnopqrstuvwxyz" },
     { "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" },
-    { "12345678901234567890123456789012345678901234567890123456789012"
-      "345678901234567890" }
+    { ("12345678901234567890123456789012345678901234567890123456789012"
+      "345678901234567890") }
 };
 
 static const size_t md4_test_strlen[7] =
diff --git a/library/md5.c b/library/md5.c
index d2b634f..4eea653 100644
--- a/library/md5.c
+++ b/library/md5.c
@@ -458,8 +458,8 @@
     { "message digest" },
     { "abcdefghijklmnopqrstuvwxyz" },
     { "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" },
-    { "12345678901234567890123456789012345678901234567890123456789012"
-      "345678901234567890" }
+    { ("12345678901234567890123456789012345678901234567890123456789012"
+      "345678901234567890") }
 };
 
 static const size_t md5_test_buflen[7] =
diff --git a/library/ripemd160.c b/library/ripemd160.c
index d6ee933..77acfc7 100644
--- a/library/ripemd160.c
+++ b/library/ripemd160.c
@@ -514,8 +514,8 @@
     { "abcdefghijklmnopqrstuvwxyz" },
     { "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq" },
     { "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" },
-    { "12345678901234567890123456789012345678901234567890123456789012"
-      "345678901234567890" },
+    { ("12345678901234567890123456789012345678901234567890123456789012"
+      "345678901234567890") },
 };
 
 static const size_t ripemd160_test_strlen[TESTS] =
diff --git a/library/sha512.c b/library/sha512.c
index 986037a..119f07f 100644
--- a/library/sha512.c
+++ b/library/sha512.c
@@ -527,8 +527,8 @@
 static const unsigned char sha512_test_buf[3][113] =
 {
     { "abc" },
-    { "abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmn"
-      "hijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu" },
+    { ("abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmn"
+      "hijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu") },
     { "" }
 };