tools/resolve_btfids: Compile resolve_btfids as host program

Making resolve_btfids to be compiled as host program so
we can avoid cross compile issues as reported by Nathan.

Also we no longer need HOST_OVERRIDES for BINARY target,
just for 'prepare' targets.

Fixes: 13e07691 ("tools/resolve_btfids: Alter how HOSTCC is forced")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/bpf/20230202112839.1131892-1-jolsa@kernel.org

tools/bpf/resolve_btfids/Build

+hostprogs := resolve_btfids
+
 resolve_btfids-y += main.o
 resolve_btfids-y += rbtree.o
 resolve_btfids-y += zalloc.o
@@ -7,4 +9,4 @@ resolve_btfids-y += str_error_r.o
 
 $(OUTPUT)%.o: ../../lib/%.c FORCE
 	$(call rule_mkdir)
-	$(call if_changed_dep,cc_o_c)
+	$(call if_changed_dep,host_cc_o_c)

tools/bpf/resolve_btfids/Makefile

@@ -22,6 +22,9 @@ HOST_OVERRIDES := AR="$(HOSTAR)" CC="$(HOSTCC)" LD="$(HOSTLD)" ARCH="$(HOSTARCH)
 		  EXTRA_CFLAGS="$(HOSTCFLAGS) $(KBUILD_HOSTCFLAGS)"
 
 RM      ?= rm
+HOSTCC  ?= gcc
+HOSTLD  ?= ld
+HOSTAR  ?= ar
 CROSS_COMPILE =
 
 OUTPUT ?= $(srctree)/tools/bpf/resolve_btfids/
@@ -64,7 +67,7 @@ $(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OU
 LIBELF_FLAGS := $(shell $(HOSTPKG_CONFIG) libelf --cflags 2>/dev/null)
 LIBELF_LIBS  := $(shell $(HOSTPKG_CONFIG) libelf --libs 2>/dev/null || echo -lelf)
 
-CFLAGS += -g \
+HOSTCFLAGS += -g \
           -I$(srctree)/tools/include \
           -I$(srctree)/tools/include/uapi \
           -I$(LIBBPF_INCLUDE) \
@@ -73,11 +76,11 @@ CFLAGS += -g \
 
 LIBS = $(LIBELF_LIBS) -lz
 
-export srctree OUTPUT CFLAGS Q
+export srctree OUTPUT HOSTCFLAGS Q HOSTCC HOSTLD HOSTAR
 include $(srctree)/tools/build/Makefile.include
 
 $(BINARY_IN): fixdep FORCE prepare | $(OUTPUT)
-	$(Q)$(MAKE) $(build)=resolve_btfids $(HOST_OVERRIDES)
+	$(Q)$(MAKE) $(build)=resolve_btfids
 
 $(BINARY): $(BPFOBJ) $(SUBCMDOBJ) $(BINARY_IN)
 	$(call msg,LINK,$@)