Fix missing initializations on some error paths

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/suites/test_suite_pkwrite.function b/tests/suites/test_suite_pkwrite.function
index 730bb88..733909e 100644
--- a/tests/suites/test_suite_pkwrite.function
+++ b/tests/suites/test_suite_pkwrite.function
@@ -68,6 +68,7 @@
 static void pk_write_check_common(char *key_file, int is_public_key, int is_der)
 {
     mbedtls_pk_context key;
+    mbedtls_pk_init(&key);
     unsigned char *buf = NULL;
     unsigned char *check_buf = NULL;
     unsigned char *start_buf;
@@ -78,9 +79,6 @@
 
     USE_PSA_INIT();
 
-    mbedtls_pk_init(&key);
-    USE_PSA_INIT();
-
     /* Note: if mbedtls_pk_load_file() successfully reads the file, then
        it also allocates check_buf, which should be freed on exit */
     TEST_EQUAL(mbedtls_pk_load_file(key_file, &check_buf, &check_buf_len), 0);