kstrtox: remove strtobool()

The conversion from strtobool() to kstrtobool() is completed. So
strtobool() can now be removed.

Link: https://lkml.kernel.org/r/87e3cc2547[e-mail]
Signed-off-by: Christophe JAILLET <[e-mail]>
Reviewed-by: Andy Shevchenko <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

include/linux/kstrtox.h

···
 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 extern long long simple_strtoll(const char *,char **,unsigned int);
 
-static inline int strtobool(const char *s, bool *res)
-{
-	return kstrtobool(s, res);
-}
-
 #endif	/* _LINUX_KSTRTOX_H */