Before commit [1], the value of a variable TPROGS_USER_CFLAGS was
passed to libbpf make command as a part of EXTRA_CFLAGS.
This commit makes sure that the value of TPROGS_USER_CFLAGS is still
passed to libbpf make command, in order to maintain backwards build
scripts compatibility.
[1] commit 
5a6ea7022ff4 ("samples/bpf: Remove unnecessary -I flags from libbpf EXTRA_CFLAGS")
Fixes: 5a6ea7022ff4 ("samples/bpf: Remove unnecessary -I flags from libbpf EXTRA_CFLAGS")
Suggested-by: Viktor Malik <vmalik@redhat.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Viktor Malik <vmalik@redhat.com>
Link: https://lore.kernel.org/bpf/20241204173416.142240-1-eddyz87@gmail.com
 always-y += hbm_out_kern.o
 always-y += hbm_edt_kern.o
 
-TPROGS_CFLAGS = $(TPROGS_USER_CFLAGS)
+COMMON_CFLAGS = $(TPROGS_USER_CFLAGS)
 TPROGS_LDFLAGS = $(TPROGS_USER_LDFLAGS)
 
 ifeq ($(ARCH), arm)