Get rid of "function" "keywords" in lavfilter testing code, hopefully will

make regressions tests runnable again with all shells.

Originally committed as revision 20059 to svn://svn.ffmpeg.org/ffmpeg/trunk

tests/codec-regression.sh

@@ -662,7 +662,7 @@ fi
 
 # libavfilter testing
 
-function do_lavfi() {
+do_lavfi() {
     test_name=$1
     eval test=\$do_$test_name
     vfilters=$2
@@ -678,7 +678,7 @@ function do_lavfi() {
 
 # libavfilter testing
 
-function do_lavfi() {
+do_lavfi() {
     test_name=$1
     eval test=\$do_$test_name
     vfilters=$2