The new make-4.4 does not reset '$(1)', '$(2)', etc. when do recursively
expanding. So the functions fire spontaneously. The reason for recursive
expanding might be to use $(shell ...).

To protect the code from spontaneous execution, we add a match check
'$(0)' to the function name. The '$(0)' variable must always have the
name of our function at the time of the call. If this is not the case,
then we are out of the $(call ...) context.

From make documentation:

| The syntax of the 'call' function is:
|
|      $(call VARIABLE,PARAM,PARAM,...)
|
| When 'make' expands this function, it assigns each PARAM to temporary
| variables '$(1)', '$(2)', etc.  The variable '$(0)' will contain
| VARIABLE.

Fix ALT bug 44561

See also:
https://github.com/osboot/make-initrd/commit/60afcd997affe150fe1153006ffcc1adac735710