gitk: Use the UI font for the diff/old version/new version radio buttons

This makes the radio buttons for selecting whether to see the full diff,
the old version or the new version use the same font as the other user
interface elements.

Signed-off-by: Paul Mackerras <paulus@samba.org>

gitk

@@ -830,11 +830,11 @@ proc makewindow {} {
     lappend entries $sstring
     trace add variable searchstring write incrsearch
     pack $sstring -side left -expand 1 -fill x
-    radiobutton .bleft.mid.diff -text "Diff" \
+    radiobutton .bleft.mid.diff -text "Diff" -font uifont \
 	-command changediffdisp -variable diffelide -value {0 0}
-    radiobutton .bleft.mid.old -text "Old version" \
+    radiobutton .bleft.mid.old -text "Old version" -font uifont \
 	-command changediffdisp -variable diffelide -value {0 1}
-    radiobutton .bleft.mid.new -text "New version" \
+    radiobutton .bleft.mid.new -text "New version" -font uifont \
 	-command changediffdisp -variable diffelide -value {1 0}
     label .bleft.mid.labeldiffcontext -text "      Lines of context: " \
 	-font uifont