b43legacy: Fix warnings from gcc 4.6.0

gcc 4.6.0 warnings for b43legacy:

  CC [M]  drivers/net/wireless/b43legacy/main.o
drivers/net/wireless/b43legacy/main.c: In function ‘b43legacy_request_firmware’:
drivers/net/wireless/b43legacy/main.c:1567:6: warning: variable ‘tmshigh’ set but not used [-Wunused-but-set-variable]
drivers/net/wireless/b43legacy/main.c: In function ‘b43legacy_op_dev_config’:
drivers/net/wireless/b43legacy/main.c:2637:6: warning: variable ‘antenna_rx’ set but not used [-Wunused-but-set-variable]
drivers/net/wireless/b43legacy/main.c: In function ‘b43legacy_op_bss_info_changed’:
drivers/net/wireless/b43legacy/main.c:2778:24: warning: variable ‘phy’ set but not used [-Wunused-but-set-variable]
drivers/net/wireless/b43legacy/xmit.c: In function ‘generate_txhdr_fw3’:
drivers/net/wireless/b43legacy/xmit.c:324:7: warning: variable ‘rts_rate_ofdm’ set but not used [-Wunused-but-set-variable]
  CC [M]  drivers/net/wireless/b43legacy/dma.o
drivers/net/wireless/b43legacy/dma.c: In function ‘free_all_descbuffers’:
drivers/net/wireless/b43legacy/dma.c:820:36: warning: variable ‘desc’ set but not used [-Wunused-but-set-variable]
drivers/net/wireless/b43legacy/dma.c: In function ‘b43legacy_dma_tx’:
drivers/net/wireless/b43legacy/dma.c:1377:28: warning: variable ‘info’ set but not used [-Wunused-but-set-variable]
drivers/net/wireless/b43legacy/dma.c:1374:24: warning: variable ‘hdr’ set but not used [-Wunused-but-set-variable]
drivers/net/wireless/b43legacy/dma.c: In function ‘b43legacy_dma_handle_txstatus’:
drivers/net/wireless/b43legacy/dma.c:1438:36: warning: variable ‘desc’ set but not used [-Wunused-but-set-variable]

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>