Spelling fix

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index f1e6cf4..fc781ea 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -1772,7 +1772,7 @@
             -c "a session has been resumed"
 
 # For reasons that aren't fully understood, this test randomly fails with high
-# probabiliby with OpenSSL 1.0.2g on the CI, see #5012.
+# probability with OpenSSL 1.0.2g on the CI, see #5012.
 requires_openssl_next
 run_test    "Session resume using tickets, DTLS: openssl client" \
             "$P_SRV dtls=1 debug_level=3 tickets=1" \
@@ -1957,7 +1957,7 @@
             -c "a session has been resumed"
 
 # For reasons that aren't fully understood, this test randomly fails with high
-# probabiliby with OpenSSL 1.0.2g on the CI, see #5012.
+# probability with OpenSSL 1.0.2g on the CI, see #5012.
 requires_openssl_next
 run_test    "Session resume using cache, DTLS: openssl client" \
             "$P_SRV dtls=1 debug_level=3 tickets=0" \