efivars: fix warnings when CONFIG_PSTORE=n

efivars: fix warnings when CONFIG_PSTORE=n

commit b728a5c806fb36f9adebf2a862bbd015e074afca upstream.

drivers/firmware/efivars.c:161: warning: ‘utf16_strlen’ defined but not used
utf16_strlen() is only used inside CONFIG_PSTORE - make this "static inline"
to shut the compiler up [thanks to hpa for the suggestion].

drivers/firmware/efivars.c:602: warning: initialization from incompatible pointer type
Between v1 and v2 of this patch series we decided to make the "part" number
unsigned - but missed fixing the stub version of efi_pstore_write()

Acked-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Mike Waychison <mikew@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
[took the static part of the patch, not the pstore part, for 3.0-stable,
to fix the compiler warning we had - gregkh]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>