linux-user: fix argument type declaration of rt_sigqueinfo() syscall

Change the type of the first argument of rt_sigqueinfo() from int to pid_t
in the syscall declaration to match specifications of the system call.

Proper spacing is added to satisfy checkpatch.pl.

Signed-off-by: Miloš Stojanović <Milos.Stojanovic@rt-rk.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
