crypto: caam - add allocation failure handling in SPRINTFCAT macro

GFP_ATOMIC memory allocation could fail.
In this case, avoid NULL pointer dereference and notify user.

Cc: <stable@vger.kernel.org> # 3.2+
Cc: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Horia Geanta <horia.geanta@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/caam/error.c

@@ -16,9 +16,13 @@
 	char *tmp;						\
 								\
 	tmp = kmalloc(sizeof(format) + max_alloc, GFP_ATOMIC);	\
-	sprintf(tmp, format, param);				\
-	strcat(str, tmp);					\
-	kfree(tmp);						\
+	if (likely(tmp)) {					\
+		sprintf(tmp, format, param);			\
+		strcat(str, tmp);				\
+		kfree(tmp);					\
+	} else {						\
+		strcat(str, "kmalloc failure in SPRINTFCAT");	\
+	}							\
 }
 
 static void report_jump_idx(u32 status, char *outstr)