usb: s3c_udc_otg: fix GCC 4.6 build warnings

usb: s3c_udc_otg: fix GCC 4.6 build warnings

Fix:
In file included from s3c_udc_otg.c:216:0:
s3c_udc_otg_xfer_dma.c: In function 'complete_tx':
s3c_udc_otg_xfer_dma.c:280:33: warning: variable 'is_short' set but not used
s3c_udc_otg_xfer_dma.c:280:6: warning: variable 'ep_tsr' set but not used
s3c_udc_otg_xfer_dma.c: In function 's3c_udc_irq':
s3c_udc_otg_xfer_dma.c:469:16: warning: variable 'flags' set but not used
s3c_udc_otg_xfer_dma.c:468:18: warning: variable 'gintmsk' set but not used
s3c_udc_otg_xfer_dma.c: In function 's3c_queue':
s3c_udc_otg_xfer_dma.c:582:14: warning: variable 'gintsts' set but not used
s3c_udc_otg_xfer_dma.c:581:16: warning: variable 'flags' set but not used
s3c_udc_otg_xfer_dma.c: In function 's3c_ep0_read':
s3c_udc_otg_xfer_dma.c:778:6: warning: variable 'ret' set but not used
s3c_udc_otg_xfer_dma.c: In function 's3c_udc_set_halt':
s3c_udc_otg_xfer_dma.c:1020:16: warning: variable 'flags' set but not used
s3c_udc_otg_xfer_dma.c: In function 's3c_ep0_setup':
s3c_udc_otg_xfer_dma.c:1258:13: warning: initialization from incompatible
pointer type [enabled by default]
s3c_udc_otg_xfer_dma.c:1239:16: warning: variable 'is_in' set but not used
s3c_udc_otg_xfer_dma.c:1239:9: warning: variable 'bytes' set but not used
s3c_udc_otg.c: In function 'usb_gadget_register_driver':
s3c_udc_otg.c:292:16: warning: variable 'flags' set but not used
s3c_udc_otg.c: In function 'usb_gadget_unregister_driver':
s3c_udc_otg.c:338:16: warning: variable 'flags' set but not used
s3c_udc_otg.c: In function 's3c_ep_enable':
s3c_udc_otg.c:582:16: warning: variable 'flags' set but not used
s3c_udc_otg.c: In function 's3c_ep_disable':
s3c_udc_otg.c:646:16: warning: variable 'flags' set but not used
s3c_udc_otg.c: In function 's3c_dequeue':
s3c_udc_otg.c:704:16: warning: variable 'flags' set but not used

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Lukasz Majewski <l.majewski@samsung.com>
Cc: Remy Bohmer <linux@bohmer.net>