seq_file: add seq_escape_str() as replica of string_escape_str()

In some cases we want to escape characters from NULL-terminated strings.
Add seq_escape_str() as replica of string_escape_str() for that.

Link: https://lkml.kernel.org/r/20210504180819.73127-13-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>

include/linux/seq_file.h

@@ -128,6 +128,13 @@ void seq_put_hex_ll(struct seq_file *m, const char *delimiter,
 
 void seq_escape_mem(struct seq_file *m, const char *src, size_t len,
 		    unsigned int flags, const char *esc);
+
+static inline void seq_escape_str(struct seq_file *m, const char *src,
+				  unsigned int flags, const char *esc)
+{
+	seq_escape_mem(m, src, strlen(src), flags, esc);
+}
+
 void seq_escape(struct seq_file *m, const char *s, const char *esc);
 void seq_escape_mem_ascii(struct seq_file *m, const char *src, size_t isz);