uapi: fix linux/nfc.h userspace compilation errors

Replace sa_family_t with __kernel_sa_family_t to fix the following
linux/nfc.h userspace compilation errors:

/usr/include/linux/nfc.h:266:2: error: unknown type name 'sa_family_t'
sa_family_t sa_family;
/usr/include/linux/nfc.h:274:2: error: unknown type name 'sa_family_t'
sa_family_t sa_family;

Fixes: 23b7869c0fd0 ("NFC: add the NFC socket raw protocol")
Fixes: d646960f7986 ("NFC: Initial LLCP support")
Cc: <[e-mail]>
Signed-off-by: Dmitry V. Levin <[e-mail]>
Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/uapi/linux/nfc.h

···
 #define NFC_SE_ENABLED  0x1
 
 struct sockaddr_nfc {
-	sa_family_t sa_family;
+	__kernel_sa_family_t sa_family;
 	__u32 dev_idx;
 	__u32 target_idx;
 	__u32 nfc_protocol;
···
 
 #define NFC_LLCP_MAX_SERVICE_NAME 63
 struct sockaddr_nfc_llcp {
-	sa_family_t sa_family;
+	__kernel_sa_family_t sa_family;
 	__u32 dev_idx;
 	__u32 target_idx;
 	__u32 nfc_protocol;