Fix typo.

Change-Id: I5a2d44f326bf173bed24aa95e0855c07c8d37d50
Reviewed-on: https://boringssl-review.googlesource.com/10371
Reviewed-by: David Benjamin <davidben@google.com>

ssl/test/PORTING.md

diff --git a/ssl/test/PORTING.md b/ssl/test/PORTING.md
index 8cd147b..1d5ac57 100644
--- a/ssl/test/PORTING.md
+++ b/ssl/test/PORTING.md
@@ -88,7 +88,7 @@
 
 ### Malloc Tests
 
-The test runner can only be used to stress malloc failure
+The test runner can also be used to stress malloc failure
 codepaths. If passed `-malloc-test=0`, the runner will run each test
 repeatedly with an incrementing `MALLOC_NUMBER_TO_FAIL` environment
 variable. The shim should then replace the malloc implementation with