libbpf: Fix KERNEL_VERSION macro

mainline inclusion
from mainline-5.13-rc1
commit 1e1032b0
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1e1032b0c4afaed7739a6681ff6b4cb120b82994

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Add missing ')' for KERNEL_VERSION macro.
Signed-off-by: NHengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210405040119.802188-1-hengqi.chen@gmail.com
(cherry picked from commit 1e1032b0)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

tools/lib/bpf/bpf_helpers.h

@@ -51,7 +51,7 @@
 #endif
 
 #ifndef KERNEL_VERSION
-#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + ((c) > 255 ? 255 : (c))
+#define KERNEL_VERSION(a, b, c) (((a) << 16) + ((b) << 8) + ((c) > 255 ? 255 : (c)))
 #endif
 
 /*