The function safexcel_try_push_requests  is local to the source and does
not need to be in global scope, so make it static.

Cleans up sparse warning:
symbol 'safexcel_try_push_requests' was not declared. Should it be static?
Signed-off-by: Colin Ian King <colin.king@canonical.com>
[Antoine: fixed alignment]
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>