Kconfig.ubsan: Remove CONFIG_UBSAN_REPORT_FULL from documentation

There is no indication in the history that such an option was merged to
mainline.

Fixes: c637693 ("ubsan: remove UBSAN_MISC in favor of individual options")
Signed-off-by: Stefan Wiehler <stefan.wiehler@nokia.com>
Link: https://patch.msgid.link/20260107114833.2030995-1-stefan.wiehler@nokia.com
Signed-off-by: Kees Cook <kees@kernel.org>

Author: sephalon

lib/Kconfig.ubsan

@@ -104,7 +104,7 @@ config UBSAN_DIV_ZERO
 	  This option enables -fsanitize=integer-divide-by-zero which checks
 	  for integer division by zero. This is effectively redundant with the
 	  kernel's existing exception handling, though it can provide greater
-	  debugging information under CONFIG_UBSAN_REPORT_FULL.
+	  debugging information.
 
 config UBSAN_UNREACHABLE
 	bool "Perform checking for unreachable code"