Fix VMS installation - $config{pointer_size} -> $target{pointer_size}

Configurations/descrip.mms.tmpl uses $target{pointer_size}, not
$config{pointer_size}, so the same should be used in installation
scripts, for consistency.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from #16842)

VMS/openssl_ivp.com.in

@@ -15,7 +15,7 @@ $	OPENSSLDIR_ = F$PARSE("A.;",OPENSSLDIR,,,"NO_CONCEAL") -
 		     - ".][000000" - "[000000." - "][" - "]A.;" + "."
 $
 $	v    := {- sprintf "%02d", split(/\./, $config{version}) -}
-$	pz   := {- $config{pointer_size} -}
+$	pz   := {- $target{pointer_size} -}
 $	
 $	@'INSTALLTOP_'SYS$STARTUP]openssl_startup'v'
 $	@'INSTALLTOP_'SYS$STARTUP]openssl_utils'v'

VMS/openssl_shutdown.com.in

@@ -27,7 +27,7 @@ $
 $	! Abbrevs
 $	DEAS := DEASSIGN /NOLOG 'P1'
 $	sv   := {- sprintf "%02d%02d", split m|\.|, $config{shlib_version} -}
-$	pz   := {- $config{pointer_size} -}
+$	pz   := {- $target{pointer_size} -}
 $
 $	DEAS OSSL$DATAROOT
 $	DEAS OSSL$INSTROOT

VMS/openssl_startup.com.in

@@ -89,7 +89,7 @@ $	! Abbrevs
 $	DEFT := DEFINE /TRANSLATION=CONCEALED /NOLOG 'P1'
 $	DEF  := DEFINE /NOLOG 'P1'
 $	sv   := {- sprintf "%02d%02d", split m|\.|, $config{shlib_version} -}
-$	pz   := {- $config{pointer_size} -}
+$	pz   := {- $target{pointer_size} -}
 $
 $	DEFT OSSL$DATAROOT		'OPENSSLDIR_']
 $	DEFT OSSL$INSTROOT		'INSTALLTOP_']