tools/vm/page_owner_sort.c: avoid repeated judgments

I noticed a detail that needs to be adjusted.  When judging whether a page
is allocated by vmalloc, the value of the variable "tmp" was repeatedly
judged, so the code was adjusted.

This work is coauthored by Yinan Zhang, Jiajian Ye, Shenghong Han, Chongxi
Zhao, Yuhong Feng and Yongqiang Liu.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Yixuan Cao <[email protected]>
Cc: Chongxi Zhao <[email protected]>
Cc: Haowen Bai <[email protected]>
Cc: Jiajian Ye <[email protected]>
Cc: Sean Anderson <[email protected]>
Cc: Shenghong Han <[email protected]>
Cc: Yinan Zhang <[email protected]>
Cc: Yongqiang Liu <[email protected]>
Cc: Yuhong Feng <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

tools/vm/page_owner_sort.c

@@ -444,10 +444,8 @@ static int get_allocator(const char *buf, const char *migrate_info)
 			tmp--;
 		first_line = ++tmp;
 		tmp = strstr(tmp, "alloc_pages");
-		if (tmp) {
-			if (tmp && first_line <= tmp && tmp < second_line)
-				allocator |= ALLOCATOR_VMALLOC;
-		}
+		if (tmp && first_line <= tmp && tmp < second_line)
+			allocator |= ALLOCATOR_VMALLOC;
 	}
 	if (allocator == 0)
 		allocator = ALLOCATOR_OTHERS;