sparc: fix unused variable warnings

sparc: fix unused variable warnings

Fix the build warnings:
board.c: In function 'board_init_f':
board.c:179:8: warning: unused variable 'e'
board.c:178:6: warning: unused variable 'i'
board.c:173:13: warning: unused variable 'cmdtp'
bootm.c: In function 'do_bootm_linux':
bootm.c:101:28: warning: unused variable 'kernend'
bootm.c:101:15: warning: unused variable 'initrd_addr'
bootm.c:100:26: warning: unused variable 'checksum'
bootm.c:100:21: warning: unused variable 'len'
bootm.c:100:15: warning: unused variable 'data'

Signed-off-by: Mike Frysinger <vapier@gentoo.org>