mm/memory_hotplug.c: s/is/if

Correct typo in comment.

Link: http://lkml.kernel.org/r/1568233954-3913-1-git-send-email-jrdr.linux@gmail.comSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/memory_hotplug.c

@@ -1793,7 +1793,7 @@ void __remove_memory(int nid, u64 start, u64 size)
 {
 
 	/*
-	 * trigger BUG() is some memory is not offlined prior to calling this
+	 * trigger BUG() if some memory is not offlined prior to calling this
 	 * function
 	 */
 	if (try_remove_memory(nid, start, size))