ucs2_string: add module description

Modules without a description now cause a warning:

WARNING: modpost: missing MODULE_DESCRIPTION() in lib/ucs2_string.o

Link: https://lkml.kernel.org/r/20250324173242.1501003-7-arnd@kernel.org
Fixes: 6c6c1fc ("modpost: require a MODULE_DESCRIPTION()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Stehen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: arndb

lib/ucs2_string.c

@@ -165,4 +165,5 @@ ucs2_as_utf8(u8 *dest, const ucs2_char_t *src, unsigned long maxlength)
 }
 EXPORT_SYMBOL(ucs2_as_utf8);
 
+MODULE_DESCRIPTION("UCS2 string handling");
 MODULE_LICENSE("GPL v2");