Bug 941127 - Fix enable flag for NFC in configure.in. r=mwu

configure.in

@@ -7319,7 +7319,7 @@ AC_SUBST(MOZ_B2G_BT_BLUEDROID)
 dnl ========================================================
 dnl = Enable NFC Interface for B2G (Gonk usually)
 dnl ========================================================
-MOZ_ARG_ENABLE_BOOL(b2g-nfc,
+MOZ_ARG_ENABLE_BOOL(nfc,
 [  --enable-nfc         Set compile flags necessary for compiling NFC API ],
     MOZ_NFC=1,
     MOZ_NFC= )