scripts: Refer to commands instead of actions in help output

scripts/dpkg-architecture.pl

@@ -44,7 +44,7 @@ later for copying conditions. There is NO warranty.
 
 sub usage {
     printf _g(
-"Usage: %s [<option> ...] [<action>]
+"Usage: %s [<option> ...] [<command>]
 
 Options:
   -a<debian-arch>    set current Debian architecture.
@@ -52,7 +52,7 @@ Options:
   -L                 list valid architectures.
   -f                 force flag (override variables set in environment).
 
-Actions:
+Commands:
   -l                 list variables (default).
   -e<debian-arch>    compare with current Debian architecture.
   -i<arch-alias>     check if current Debian architecture is <arch-alias>.

scripts/dpkg-buildflags.pl

@@ -38,9 +38,9 @@ later for copying conditions. There is NO warranty.
 
 sub usage {
     printf _g(
-"Usage: %s [<action>]
+"Usage: %s [<command>]
 
-Actions:
+Commands:
   --get <flag>       output the requested flag to stdout.
   --origin <flag>    output the origin of the flag to stdout:
                      value is one of vendor, system, user, env.

scripts/dpkg-vendor.pl

@@ -38,12 +38,12 @@ later for copying conditions. There is NO warranty.
 
 sub usage {
     printf _g(
-"Usage: %s [<option> ...] [<action>]
+"Usage: %s [<option> ...] [<command>]
 
 Options:
   --vendor <vendor>       assume <vendor> is the current vendor
 
-Actions:
+Commands:
   --is <vendor>           returns true if current vendor is <vendor>.
   --derives-from <vendor> returns true if current vendor derives from <vendor>.
   --query <field>         print the content of the vendor-specific field.