f2fs: use seq_puts()/seq_putc() rather than seq_printf() where possible

For string without format specifiers, using seq_puts()/seq_putc()
instead of seq_printf().

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index fd12b7f..a84b0a8 100644
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -253,21 +253,21 @@
 			   si->nats, NM_WOUT_THRESHOLD);
 		seq_printf(s, "  - SITs: %5d\n  - free_nids: %5d\n",
 			   si->sits, si->fnids);
-		seq_printf(s, "\nDistribution of User Blocks:");
-		seq_printf(s, " [ valid | invalid | free ]\n");
-		seq_printf(s, "  [");
+		seq_puts(s, "\nDistribution of User Blocks:");
+		seq_puts(s, " [ valid | invalid | free ]\n");
+		seq_puts(s, "  [");
 
 		for (j = 0; j < si->util_valid; j++)
-			seq_printf(s, "-");
-		seq_printf(s, "|");
+			seq_putc(s, '-');
+		seq_putc(s, '|');
 
 		for (j = 0; j < si->util_invalid; j++)
-			seq_printf(s, "-");
-		seq_printf(s, "|");
+			seq_putc(s, '-');
+		seq_putc(s, '|');
 
 		for (j = 0; j < si->util_free; j++)
-			seq_printf(s, "-");
-		seq_printf(s, "]\n\n");
+			seq_putc(s, '-');
+		seq_puts(s, "]\n\n");
 		seq_printf(s, "SSR: %u blocks in %u segments\n",
 			   si->block_count[SSR], si->segment_count[SSR]);
 		seq_printf(s, "LFS: %u blocks in %u segments\n",