staging: rtl8723bs: rework debug configuration handling

I ran into this warning during randconfig testing:

drivers/staging/rtl8723bs/os_dep/rtw_proc.c: In function 'rtw_adapter_proc_deinit':
drivers/staging/rtl8723bs/os_dep/rtw_proc.c:738:25: error: unused variable 'drv_proc' [-Werror=unused-variable]
drivers/staging/rtl8723bs/os_dep/rtw_proc.c: In function 'rtw_adapter_proc_replace':
drivers/staging/rtl8723bs/os_dep/rtw_proc.c:762:25: error: unused variable 'drv_proc' [-Werror=unused-variable]

The problem is that the code procfs code gets built even when CONFIG_PROC_FS
is disabled, but some functions are turned into empty stubs then. This
is easily addressed by adding an #ifdef around the definition of the
CONFIG_PROC_DEBUG macro.

However, I could not bear looking at the macro name that clashes with the
Kconfig name space, so I also renamed it to simply PROC_DEBUG, along with
the other rtl8723bs specific CONFIG_DEBUG_* macros that I renamed the same
way. This is consistent with how we handle the same checks in the non-staging
rtlwifi driver.

As the code path for !CONFIG_PROC_DEBUG had not been tested properly, it
turned out to be incorrect and requires adding 'static inline' annotations
for the stub handlers, and moving some variables around.

Fixes: 554c0a3a ("staging: Add rtl8723bs sdio wifi driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>