Link with $(CC), not the hardcoded cc.

diff -Nrup a/makefile b/makefile
--- a/makefile	2024-09-24 22:38:53.000000000 +0200
+++ b/makefile	2026-10-22 17:22:16.949308806 +0200
@@ -136,10 +136,10 @@ DIST_TAR_FLAGS = cvf
 all: $(UNIX_BINARIES)
 
 pdisk: $(UNIX_OBJECTS)
-	cc -o pdisk $(UNIX_OBJECTS)
+	$(CC) -o pdisk $(UNIX_OBJECTS)
 
 cvt_pt: $(CVT_OBJECTS)
-	cc -o cvt_pt $(CVT_OBJECTS)
+	$(CC) -o cvt_pt $(CVT_OBJECTS)
 
 tags:	$(MAC_SOURCE) $(UNIX_SOURCE)
 	ctags $(MAC_SOURCE) $(UNIX_SOURCE)