Fix zgrep(1) wrapper regression, add test

@bdrewery reported D48873 broke "bzgrep -q '1 2' /var/log/messages.0.bz2"
The mistake was in using $* instead of "$@" (I suspect $* is never right).

Reported by:	bdrewery
Reviewed by:	markj
Approved by:	markj
Fixes:		1070477cc8 ("Fix remaining zgrep(1) wrapper script regressions")
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D54217

usr.bin/grep/tests/grep_freebsd_test.sh

@@ -117,6 +117,15 @@ color_dupe_body()
 	atf_check -o match:"^ +1 color.out" wc -l color.out
 }
 
+atf_test_case qflag
+qflag_body()
+{
+	# Test whitespace in argument
+	printf "1 2 3 4\n5 6 7 8\n" > in
+
+	atf_check zgrep -q '1 2' in
+}
+
 atf_init_test_cases()
 {
 	atf_add_test_case grep_r_implied
@@ -124,4 +133,5 @@ atf_init_test_cases()
 	atf_add_test_case gnuext
 	atf_add_test_case zflag
 	atf_add_test_case color_dupe
+	atf_add_test_case qflag
 }

usr.bin/grep/zgrep.sh

@@ -109,7 +109,7 @@ do
 	    grep_args="${grep_args} ${pre}"
 	    shift
 	    # Put back partial arg
-	    set -- "-${post}" $*
+	    set -- "-${post}" "$@"
 	    ;;
 	-[ABCDdefm])
 	    if [ $# -lt 2 ]