misc: sgi-xp: remove meaningless null check before kfree

kfree has taken null pointer into account. so check the null pointer
before kfree is meaningless.

Signed-off-by: zhong jiang <[e-mail]>
Acked-by: Robin Holt <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/sgi-xp/xpc_partition.c

···
 			len = L1_CACHE_ALIGN(len);
 
 		if (len > buf_len) {
-			if (buf_base != NULL)
-				kfree(buf_base);
+			kfree(buf_base);
 			buf_len = L1_CACHE_ALIGN(len);
 			buf = xpc_kmalloc_cacheline_aligned(buf_len, GFP_KERNEL,
 							    &buf_base);