bash-completion: simplify pid listing

Changing directory in subshell does not effect parent process, so this is
better and possibly quicker way to list pids.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

bash-completion/nsenter

@@ -15,7 +15,7 @@ _nsenter_module()
 			;;
 		'-t'|'--target')
 			local PIDS
-			PIDS=$(for I in /proc/[0-9]*; do echo ${I##"/proc/"}; done)
+			PIDS=$(cd /proc && echo [0-9]*)
 			COMPREPLY=( $(compgen -W "$PIDS" -- $cur) )
 			return 0
 			;;

bash-completion/prlimit

@@ -6,7 +6,7 @@ _prlimit_module()
 	prev="${COMP_WORDS[COMP_CWORD-1]}"
 	case $prev in
 		'-p'|'--pid')
-			PIDS=$(for I in /proc/[0-9]*; do echo ${I##"/proc/"}; done)
+			PIDS=$(cd /proc && echo [0-9]*)
 			COMPREPLY=( $(compgen -W "$PIDS" -- $cur) )
 			return 0
 			;;

bash-completion/renice

@@ -17,7 +17,7 @@ _renice_module()
 			;;
 		'-p'|'--pid')
 			local PIDS
-			PIDS=$(for I in /proc/[0-9]*; do echo ${I##"/proc/"}; done)
+			PIDS=$(cd /proc && echo [0-9]*)
 			COMPREPLY=( $(compgen -W "$PIDS" -- $cur) )
 			return 0
 			;;

bash-completion/taskset

@@ -25,7 +25,7 @@ _taskset_module()
 			# setting an affinity the optarg has to be cpu
 			# mask.  The following is good only for getting
 			# affinity.
-			PIDS=$(for I in /proc/[0-9]*; do echo ${I##"/proc/"}; done)
+			PIDS=$(cd /proc && echo [0-9]*)
 			COMPREPLY=( $(compgen -W "$PIDS" -- $cur) )
 			return 0
 			;;