init/Kconfig: fix typo (usafe -> unsafe)

Fix the help text for the PRINTK_SAFE_LOG_BUF_SHIFT setting.

Link: https://lkml.kernel.org/r/20230109201837.23873-1-eliasfleckenstein@web.deSigned-off-by: Lizzy Fleckenstein <eliasfleckenstein@web.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

init/Kconfig

@@ -776,7 +776,7 @@ config PRINTK_SAFE_LOG_BUF_SHIFT
 	depends on PRINTK
 	help
 	  Select the size of an alternate printk per-CPU buffer where messages
-	  printed from usafe contexts are temporary stored. One example would
+	  printed from unsafe contexts are temporary stored. One example would
 	  be NMI messages, another one - printk recursion. The messages are
 	  copied to the main log buffer in a safe context to avoid a deadlock.
 	  The value defines the size as a power of 2.