Update docs/code-quality/c6308.md

Co-authored-by: Michael Squires <[email protected]>

Author: MugBergerFries

docs/code-quality/c6308.md

@@ -19,7 +19,7 @@ Code analysis name: REALLOCLEAK
 
 ## Example
 
-The following sample code generates this warning. This issue stems from the assignment of x to the return value from realloc. If realloc fails and returns a null pointer, then x will fail to be freed:
+The following sample code generates this warning. This issue stems from the assignment of `x` to the return value from realloc. If realloc fails and returns a NULL pointer, then `x` will fail to be freed:
 
 ```cpp
 #include <malloc.h>