scripts/kallsyms.c Make the comment up-to-date with current implementation

The comment in scripts/kallsyms.c describing the usage of
scripts/kallsyms does not reflect the latest implementation.
Fix the comment to be equivalent to what the usage() function prints.
Signed-off-by: NYuma Ueda <cyan@0x00a1e9.dev>
Reviewed-by: NMiguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/r/20221118133631.4554-1-cyan@0x00a1e9.devSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

scripts/kallsyms.c

@@ -5,7 +5,8 @@
  * This software may be used and distributed according to the terms
  * of the GNU General Public License, incorporated herein by reference.
  *
- * Usage: nm -n vmlinux | scripts/kallsyms [--all-symbols] > symbols.S
+ * Usage: kallsyms [--all-symbols] [--absolute-percpu]
+ *                         [--base-relative] in.map > out.S
  *
  *      Table compression uses all the unused char codes on the symbols and
  *  maps these to the most used substrings (tokens). For instance, it might