proc: rename "catch" function argument

"catch" is reserved keyword in C++, rename it to something both gcc and
g++ accept.

Rename "ign" for symmetry.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200331210905.GA31680@avx2Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/proc/array.c

@@ -248,8 +248,8 @@ void render_sigset_t(struct seq_file *m, const char *header,
 	seq_putc(m, '\n');
 }
 
-static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *ign,
-				    sigset_t *catch)
+static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *sigign,
+				    sigset_t *sigcatch)
 {
 	struct k_sigaction *k;
 	int i;
@@ -257,9 +257,9 @@ static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *ign,
 	k = p->sighand->action;
 	for (i = 1; i <= _NSIG; ++i, ++k) {
 		if (k->sa.sa_handler == SIG_IGN)
-			sigaddset(ign, i);
+			sigaddset(sigign, i);
 		else if (k->sa.sa_handler != SIG_DFL)
-			sigaddset(catch, i);
+			sigaddset(sigcatch, i);
 	}
 }