seq_file: convert seq_escape() to use seq_escape_str()

Convert seq_escape() to use seq_escape_str() rather than open coding it.

Note, for now we leave it as an exported symbol due to some old code that
can't tolerate ctype.h being (indirectly) included.

Link: https://lkml.kernel.org/r/20210504180819.73127-14-andriy.shevchenko@linux.intel.comSigned-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/seq_file.c

@@ -392,12 +392,7 @@ EXPORT_SYMBOL(seq_escape_mem);
  */
 void seq_escape(struct seq_file *m, const char *s, const char *esc)
 {
-	char *buf;
-	size_t size = seq_get_buf(m, &buf);
-	int ret;
-
-	ret = string_escape_str(s, buf, size, ESCAPE_OCTAL, esc);
-	seq_commit(m, ret < size ? ret : -1);
+	seq_escape_str(m, s, ESCAPE_OCTAL, esc);
 }
 EXPORT_SYMBOL(seq_escape);