ARM: plat-pxa: remove use of seq_printf return value

ARM: plat-pxa: remove use of seq_printf return value

The seq_printf return value, because it's frequently misused,
(as it is here, it doesn't return # of chars emitted) will
eventually be converted to void.

See: commit 1f33c41c03da ("seq_file: Rename seq_overflow() to
     seq_has_overflowed() and make public")

Signed-off-by: Joe Perches <[email protected]>
Cc: Russell King <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>