tools: runqslower: Add EXTRA_CFLAGS and EXTRA_LDFLAGS support

This makes it possible to add sanitizer flags.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230210001210.395194-3-iii@linux.ibm.com

tools/bpf/runqslower/Makefile

@@ -13,6 +13,8 @@ BPF_DESTDIR := $(BPFOBJ_OUTPUT)
 BPF_INCLUDE := $(BPF_DESTDIR)/include
 INCLUDES := -I$(OUTPUT) -I$(BPF_INCLUDE) -I$(abspath ../../include/uapi)
 CFLAGS := -g -Wall $(CLANG_CROSS_FLAGS)
+CFLAGS += $(EXTRA_CFLAGS)
+LDFLAGS += $(EXTRA_LDFLAGS)
 
 # Try to detect best kernel BTF source
 KERNEL_REL := $(shell uname -r)