test: Remove unnecessary "exit" calls

test/t-02-exim/run.sh

@@ -30,7 +30,6 @@ check_hostaliases
 
 if ! .exim4/exim4 --version > /dev/null; then
 	skip "exim4 binary at .exim4/exim4 is not functional"
-	exit 0
 fi
 
 # Create a temporary directory for exim4 to use, and generate the exim4

test/t-11-dovecot/run.sh

@@ -14,7 +14,6 @@ check_hostaliases
 
 if ! dovecot --version > /dev/null; then
 	skip "dovecot not installed"
-	exit 0
 fi
 
 # Create a temporary directory for dovecot to use, and generate the dovecot

test/t-15-driusan_dkim/run.sh

@@ -12,7 +12,6 @@ check_hostaliases
 for binary in dkimsign dkimverify dkimkeygen; do
 	if ! command -v $binary > /dev/null; then
 		skip "$binary binary not found"
-		exit 0
 	fi
 done
 

test/t-16-spf/run.sh

@@ -44,8 +44,8 @@ wait_until_ready 2025
 
 function launch_minidns() {
 	if [ "$MINIDNS" != "" ]; then
-		kill $MINIDNS
-		wait $MINIDNS || true
+		kill "$MINIDNS"
+		wait "$MINIDNS" || true
 	fi
 	cp "$1" .zones
 	minidns_bg --addr=":9053" -zones=.zones >> .minidns.log 2>&1

test/t-18-haproxy/run.sh

@@ -10,7 +10,6 @@ mkdir -p .logs
 
 if ! haproxy -v > /dev/null; then
 	skip "haproxy binary not found"
-	exit 0
 fi
 
 # Set a 2m timeout: if there are issues with haproxy, the wait tends to hang