Deindent syscall_enter by removing unnecessary braces. No code changes.

Deindent syscall_enter by removing unnecessary braces. No code changes.

syscall_enter has many long (>80 columns) lines.
It is aggravated by the fact that it has a lot of {} blocks
which are not necessary (the code is the same without them).
This patch removes {}s and deindents affected lines.
While at it, it indents ifdefs so that nesting is easier to track,
and adds a few spaces in the expressions, such as
"tcp->u_nargs*sizeof..." -> "tcp->u_nargs * sizeof...".
There is no actual changes to the code here.

* syscall.c (syscall_enter): Remove unnecessary {} blocks.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>