solarized-definitions.el: fix comparison error in which-flet fset logic.
solarized-definitions.el: fix comparison error in which-flet fset logic.

flet was deprecated in 24.3, but daff304 accidentally used > 25.2 instead
of >= 24.3 as a condition. This commit fixes that.

ramLlama/emacs-color-theme-solarized,dcherian/emacs-color-theme-solarized,longouyang/emacs-color-theme-solarized,lokiiart/emacs-color-theme-solarized,bradleywright/emacs-color-theme-solarized,calve/emacs-color-theme-solarized,gugek/emacs-color-theme-solarized,dgoel/emacs-color-theme-solarized,jyp/emacs-color-theme-solarized,mattduck/emacs-color-theme-solarized,bradwright/emacs-color-theme-solarized,junag/emacs-color-theme-solarized,sellout/emacs-color-theme-solarized