bpftool: improve reproducibility

Pass -f(debug|macro)-prefix-map through CC because libbpf
build system overrides CFLAGS. Also remap STAGING_KERNEL_DIR
because it is also stored in resulting executable

Signed-off-by: Denys Zagorui <dzagorui@cisco.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>
(cherry picked from commit 120de5e02a)
Signed-off-by: Armin Kuster <akuster808@gmail.com>

meta-oe/recipes-kernel/bpftool/bpftool.bb

@@ -9,7 +9,16 @@ inherit bash-completion kernelsrc kernel-arch
 
 do_populate_lic[depends] += "virtual/kernel:do_patch"
 
-EXTRA_OEMAKE = "V=1 -C ${S}/tools/bpf/bpftool O=${B} CROSS=${TARGET_PREFIX} CC="${CC}" LD="${LD}" AR=${AR} ARCH=${ARCH}"
+EXTRA_OEMAKE = "\
+    V=1 \
+    -C ${S}/tools/bpf/bpftool \
+    O=${B} \
+    CROSS=${TARGET_PREFIX} \
+    CC="${CC} ${DEBUG_PREFIX_MAP} -fdebug-prefix-map=${STAGING_KERNEL_DIR}=${KERNEL_SRC_PATH}" \
+    LD="${LD}" \
+    AR=${AR} \
+    ARCH=${ARCH} \
+"
 
 SECURITY_CFLAGS = ""