Append -o flag explicitely, otherwise hash.o and blocks.o are generated
in ${WRKSRC} instead of ${WRKSRC}/sha256 and linking fails.

Index: Makefile.in
--- Makefile.in.orig
+++ Makefile.in
@@ -32,11 +32,11 @@ mandir = $(prefix)/share/man
 CC        = @CC@
 XCPPFLAGS = @CPPFLAGS@
 CFLAGS    = @CFLAGS@ $(XCPPFLAGS) $(DEFS) -I$(srcdir)
-ifeq ($(CC),gcc)
-CFLAGS	 += -Wall -Wformat -Werror=format-security
+#ifeq ($(CC),gcc)
+#CFLAGS	 += -Wall -Wformat -Werror=format-security
 #CFLAGS	 += -fno-omit-frame-pointer -D_FORTIFY_SOURCE=2
 #CFLAGS	 += -fstack-protector --param=ssp-buffer-size=4 -fsanitize=address,undefined
-endif
+#endif
 LDFLAGS   = @LDFLAGS@
 LIBS      = @LIBS@
 STRIP     = strip
@@ -60,6 +60,9 @@ OBJS = $(PKGNAME).o jpegmarker.o misc.o @GNUGETOPT@ \
 	md5/md5.o \
 	sha256/hash.o sha256/blocks.o \
 	sha512/hash.o sha512/blocks.o
+
+.c.o:
+	$(CC) $(CFLAGS) -o $@ -c $<
 
 $(PKGNAME):	$(OBJS)
 	$(CC) $(CFLAGS) -o $(PKGNAME) $(OBJS) $(LDFLAGS) $(LIBS)
