selftests: mm: hugepage-mmap: conform to TAP format output

Conform the layout, informational and status messages to TAP.  No
functional change is intended other than the layout of output messages.

Link: https://lkml.kernel.org/r/20240102053223.2099572-1-usama.anjum@collabora.com
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: Muhammad Usama Anjum

tools/testing/selftests/mm/hugepage-mmap.c

@@ -22,6 +22,7 @@
 #include <unistd.h>
 #include <sys/mman.h>
 #include <fcntl.h>
+#include "../kselftest.h"
 
 #define LENGTH (256UL*1024*1024)
 #define PROTECTION (PROT_READ | PROT_WRITE)
@@ -37,7 +38,7 @@
 
 static void check_bytes(char *addr)
 {
-	printf("First hex is %x\n", *((unsigned int *)addr));
+	ksft_print_msg("First hex is %x\n", *((unsigned int *)addr));
 }
 
 static void write_bytes(char *addr)
@@ -55,7 +56,7 @@ static int read_bytes(char *addr)
 	check_bytes(addr);
 	for (i = 0; i < LENGTH; i++)
 		if (*(addr + i) != (char)i) {
-			printf("Mismatch at %lu\n", i);
+			ksft_print_msg("Error: Mismatch at %lu\n", i);
 			return 1;
 		}
 	return 0;
@@ -66,26 +67,28 @@ int main(void)
 	void *addr;
 	int fd, ret;
 
+	ksft_print_header();
+	ksft_set_plan(1);
+
 	fd = memfd_create("hugepage-mmap", MFD_HUGETLB);
-	if (fd < 0) {
-		perror("memfd_create() failed");
-		exit(1);
-	}
+	if (fd < 0)
+		ksft_exit_fail_msg("memfd_create() failed: %s\n", strerror(errno));
 
 	addr = mmap(ADDR, LENGTH, PROTECTION, FLAGS, fd, 0);
 	if (addr == MAP_FAILED) {
-		perror("mmap");
 		close(fd);
-		exit(1);
+		ksft_exit_fail_msg("mmap(): %s\n", strerror(errno));
 	}
 
-	printf("Returned address is %p\n", addr);
+	ksft_print_msg("Returned address is %p\n", addr);
 	check_bytes(addr);
 	write_bytes(addr);
 	ret = read_bytes(addr);
 
 	munmap(addr, LENGTH);
 	close(fd);
 
-	return ret;
+	ksft_test_result(!ret, "Read same data\n");
+
+	ksft_exit(!ret);
 }