regen_makefile.sh: set executable name explicitly

Set the executable name in each regen_makefile.sh explicitly with -e,
instead of having it set indirectly from the first .ttcn file. Make it
consistent by placing the name on top of each of these files.

Fix for warning:
ttcn3_makefilegen: warning: File `BSC_Tests.ttcn' was given more than once for the Makefile.

Related: OS#5252
Change-Id: I5ed03f8f3ed905483620dc7bae33b617bbb8507f
diff --git a/msc/regen_makefile.sh b/msc/regen_makefile.sh
index 4ca9558..081d2cb 100755
--- a/msc/regen_makefile.sh
+++ b/msc/regen_makefile.sh
@@ -1,5 +1,7 @@
 #!/bin/sh
 
+NAME=MSC_Tests
+
 FILES="
 	*.asn
 	*.c
@@ -42,6 +44,6 @@
 	-DUSE_MTP3_DISTRIBUTOR
 "
 
-../regen-makefile.sh MSC_Tests.ttcn $FILES
+../regen-makefile.sh -e $NAME $FILES
 
 sed -i -e 's/^LINUX_LIBS = -lxml2 -lsctp/LINUX_LIBS = -lxml2 -lsctp -lfftranscode -lssl/' Makefile