Fix some cppcheck warnings

Fix some cppcheck warnings

Someone was nice enough to run this for us:

ftp://ftp.sunet.se/pub/Linux/distributions/Debian/debian/pool/main/libx/libxkbcommon/libxkbcommon_0.3.1.orig.tar.gz
[libxkbcommon-0.3.1/src/keymap.c:86]: (style) The scope of the variable 'j' can be reduced.
[libxkbcommon-0.3.1/src/keymap.c:87]: (style) The scope of the variable 'key' can be reduced.
[libxkbcommon-0.3.1/src/keysym-utf.c:843]: (style) The scope of the variable 'mid' can be reduced.
[libxkbcommon-0.3.1/src/state.c:992]: (style) The scope of the variable 'str' can be reduced.
[libxkbcommon-0.3.1/src/xkbcomp/action.c:467]: (style) The scope of the variable 'absolute' can be reduced.
[libxkbcommon-0.3.1/src/xkbcomp/rules.c:468]: (style) The scope of the variable 'consumed' can be reduced.
[libxkbcommon-0.3.1/src/xkbcomp/rules.c:862]: (style) The scope of the variable 'mlvo' can be reduced.
[libxkbcommon-0.3.1/src/xkbcomp/rules.c:863]: (style) The scope of the variable 'kccgst' can be reduced.
[libxkbcommon-0.3.1/src/xkbcomp/rules.c:865]: (style) The scope of the variable 'match_type' can be reduced.
[libxkbcommon-0.3.1/src/xkbcomp/symbols.c:753]: (style) The scope of the variable 'toAct' can be reduced.
[libxkbcommon-0.3.1/src/xkbcomp/symbols.c:1573]: (style) The scope of the variable 'key' can be reduced.
[libxkbcommon-0.3.1/test/common.c:80]: (warning) %d in format string (no. 1) requires 'int' but the argument type is 'unsigned int'.
[libxkbcommon-0.3.1/test/interactive.c:358]: (style) The scope of the variable 'nevs' can be reduced.
[libxkbcommon-0.3.1/test/interactive.c:236]: (style) Checking if unsigned variable 'nsyms' is less than zero.
[libxkbcommon-0.3.1/test/interactive.c:226]: (style) Unused variable: unicode

Signed-off-by: Ran Benita <ran234@gmail.com>