ANDROID: mld: fix pragma usage with gcc

Use the recently added pragma only when compiling with clang, otherwise
the build breaks as reported by kernelci:

  drivers/net/wireless/intel/iwlwifi/mld/d3.c:1759: error: ignoring ‘#pragma clang loop’ [-Werror=unknown-pragmas]
   1759 | #pragma clang loop unroll(disable)
        |

Cc: Todd Kjos <tkjos@google.com>
Cc: Lee Jones <joneslee@google.com>
Fixes: 5737edf385 ("ANDROID: mld: temporary workaround to fortify break")
Reported-by: kernelci.org bot <bot@kernelci.org>
Closes: https://d.kernelci.org/i/maestro:f8504377b23bbd100dea49e0f68cf83014967f25
Change-Id: Ia311b7754821ca69f0ce3ee58a507126ad2491db
Signed-off-by: Carlos Llamas <cmllamas@google.com>

drivers/net/wireless/intel/iwlwifi/mld/d3.c

@@ -1756,7 +1756,9 @@ iwl_mld_send_proto_offload(struct iwl_mld *mld,
 					  &solicited_addr);
 
 /* TODO(b/411091992): remove pragma workaround once issue is resolved. */
+#ifdef __clang__
 #pragma clang loop unroll(disable)
+#endif
 		for (j = 0; j < c; j++)
 			if (ipv6_addr_cmp(&nsc[j].dest_ipv6_addr,
 					  &solicited_addr) == 0)