[PATCH] input/misc: hp_sdc_rtc: mark an unused function as __maybe_unused

[Randy Dunlap <rdunlap@infradead.org>]

When CONFIG_PROC_FS is not set, one procfs-related function is not
used, causing a build error or warning.
Mark this function as __maybe_unused to quieten the build.

../drivers/input/misc/hp_sdc_rtc.c:268:12: warning: 'hp_sdc_rtc_proc_show' defined but not used [-Wunused-function]
  268 | static int hp_sdc_rtc_proc_show(struct seq_file *m, void *v)
      |            ^~~~~~~~~~~~~~~~~~~~

Fixes: c18bd9a1ff47 ("hp_sdc_rtc: Don't use create_proc_read_entry()")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-m68k@lists.linux-m68k.org
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: linux-parisc@vger.kernel.org
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: linux-input@vger.kernel.org
---
 drivers/input/misc/hp_sdc_rtc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -- a/drivers/input/misc/hp_sdc_rtc.c b/drivers/input/misc/hp_sdc_rtc.c
--- a/drivers/input/misc/hp_sdc_rtc.c
+++ b/drivers/input/misc/hp_sdc_rtc.c
@@ -265,7 +265,7 @@ static inline int hp_sdc_rtc_read_ct(str
 	return 0;
 }
 
-static int hp_sdc_rtc_proc_show(struct seq_file *m, void *v)
+static int __maybe_unused hp_sdc_rtc_proc_show(struct seq_file *m, void *v)
 {
 #define YN(bit) ("no")
 #define NY(bit) ("yes")