kconfig: display recursive dependency resolution hint just once

Commit 1c199f28 ("kbuild: document recursive dependency limitation
/ resolution") probably intended to show a hint along with "recursive
dependency detected!" error, but it missed to add {...} guard, and the
hint is displayed in every loop of the dep_stack traverse, annoyingly.

This error was detected by GCC's -Wmisleading-indentation when switching
to build-time generation of lexer/parser.

scripts/kconfig/symbol.c: In function ‘sym_check_print_recursive’:
scripts/kconfig/symbol.c:1150:3: warning: this ‘if’ clause does not guard... [-Wmisleading-indentation]
   if (stack->sym == last_sym)
   ^~
scripts/kconfig/symbol.c:1153:4: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘if’
    fprintf(stderr, "For a resolution refer to Documentation/kbuild/kconfig-language.txt\n");
    ^~~~~~~

I could simply add {...} to surround the three fprintf(), but I rather
chose to move the hint after the loop to make the whole message readable.

Fixes: 1c199f28

 ("kbuild: document recursive dependency limitation / resolution"
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>