kallsyms: drop duplicated ignore patterns from kallsyms.c

Now that kallsyms.c parses the output from mksysmap, some symbols have
already been dropped.

Move comments to scripts/mksysmap. Also, make the grep command readable.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/kallsyms.c

@@ -107,9 +107,6 @@ static bool is_ignored_symbol(const char *name, char type)
 
 	/* Symbol names that begin with the following are ignored.*/
 	static const char * const ignored_prefixes[] = {
-		"$",			/* local symbols for ARM, MIPS, etc. */
-		".L",			/* local labels, .LBB,.Ltmpxxx,.L__unnamed_xx,.LASANPC, etc. */
-		"__crc_",		/* modversions */
 		"__efistub_",		/* arm64 EFI stub namespace */
 		"__kvm_nvhe_$",		/* arm64 local symbols in non-VHE KVM namespace */
 		"__kvm_nvhe_.L",	/* arm64 local symbols in non-VHE KVM namespace */

scripts/mksysmap

@@ -40,5 +40,17 @@
 # 'W' or 'w'.
 #
 # Ignored prefixes:
+#  $                    - local symbols for ARM, MIPS, etc.
+#  .L                   - local labels, .LBB,.Ltmpxxx,.L__unnamed_xx,.LASANPC, etc.
 #  __crc_               - modversions
-$NM -n $1 | grep -v '\( [aNUw] \)\|\(__crc_\)\|\( \$[adt]\)\|\( \.L\)\|\( L0\)' > $2
+#
+# Ignored symbols:
+#  L0                   - for LoongArch?
+
+$NM -n $1 | grep -v		\
+	-e ' [aNUw] '		\
+	-e ' \$'		\
+	-e ' \.L'		\
+	-e ' __crc_'		\
+	-e ' L0$'		\
+> $2