history: Remove interim zstyle variables

modules/history/init.zsh

@@ -26,13 +26,12 @@ setopt HIST_BEEP                 # Beep when accessing non-existent history.
 # Variables
 #
 
-zstyle -s ':prezto:module:history' histfile '_pmh_histfile' || _pmh_histfile="${HISTFILE:-${ZDOTDIR:-$HOME}/.zsh_history}"
-zstyle -s ':prezto:module:history' histsize '_pmh_histsize' || _pmh_histsize=10000
-zstyle -s ':prezto:module:history' savehist '_pmh_savehist' || _pmh_savehist=${_pmh_histsize}
-HISTFILE="${_pmh_histfile}"  # The path to the history file.
-HISTSIZE="${_pmh_histsize}"  # The maximum number of events to save in the internal history.
-SAVEHIST="${_pmh_savehist}"  # The maximum number of events to save in the history file.
-unset _pmh_{hist{file,size},savehist}
+zstyle -s ':prezto:module:history' histfile 'HISTFILE' \
+    || HISTFILE="${HISTFILE:-${ZDOTDIR:-$HOME}/.zsh_history}" # The path to the history file.
+zstyle -s ':prezto:module:history' histsize 'HISTSIZE' \
+    || HISTSIZE=10000                                         # The maximum number of events to save in the internal history.
+zstyle -s ':prezto:module:history' savehist 'SAVEHIST' \
+    || SAVEHIST=$HISTSIZE                                     # The maximum number of events to save in the history file.
 
 #
 # Aliases