Initialize variables

This patch fixes the following -Werror=maybe-uninitialized errors:

psm_diags.c:294:10: error: 'dst_p' may be used uninitialized in this function [-Werror=maybe-uninitialized]
       if (dst_p) psmi_free(dst_p);
          ^
In file included from psm_user.h:54:0,
                 from psm_diags.c:35:
psm_utils.h:156:23: error: 'src_p' may be used uninitialized in this function [-Werror=maybe-uninitialized]
 #define psmi_free(sz) psmi_free_internal(sz)
                       ^
psm_diags.c:290:11: note: 'src_p' was declared here
     void *src_p, *dst_p;
           ^
If posix_memalign fails to return a value different than zero,
the pointers are never initialized.

Author: ana

psm_diags.c

@@ -287,7 +287,7 @@ memcpy_check_size (memcpy_fn_t fn, int *p, int *f, size_t n)
       return -1;
   }
   else {
-    void *src_p, *dst_p;
+    void *src_p = NULL, *dst_p = NULL;
     if (posix_memalign(&src_p, 64, size) != 0 ||
         posix_memalign(&dst_p, 64, size) != 0) {
       if (src_p) psmi_free(src_p);