Fix average selection in load segment.

Removed duplicate code selecting which load average to use.
Fixed load average selection being in OSX/BSD part of if, making it not work
on non OSX/BSD systems.
Optimized actually getting the load average.

powerlevel9k.zsh-theme

@@ -932,13 +932,14 @@ prompt_vpn_ip() {
   done
 }
 
+set_default POWERLEVEL9K_LOAD_WHICH 5
 prompt_load() {
   # The load segment can have three different states
   local current_state="unknown"
+  local load_select=2
+  local load_avg
   local cores
 
-  set_default POWERLEVEL9K_LOAD_WHICH 5
-
   typeset -AH load_states
   load_states=(
     'critical'      'red'
@@ -946,32 +947,38 @@ prompt_load() {
     'normal'        'green'
   )
 
-  if [[ "$OS" == "OSX" ]] || [[ "$OS" == "BSD" ]]; then
+  case "$POWERLEVEL9K_LOAD_WHICH" in
-
+    1)
-    if [[ "$POWERLEVEL9K_LOAD_WHICH" -eq 1 ]]; then
+      load_select=1
-     load_avg=$(sysctl vm.loadavg | grep -o -E '[0-9]+(\.|,)[0-9]+' | head -n 3 | sed -n 1p)
+      ;;
-    elif [[ "$POWERLEVEL9K_LOAD_WHICH" -eq 5 ]]; then
+    5)
-     load_avg=$(sysctl vm.loadavg | grep -o -E '[0-9]+(\.|,)[0-9]+' | head -n 3 | sed -n 2p)
+      load_select=2
-    else
+      ;;
-     load_avg=$(sysctl vm.loadavg | grep -o -E '[0-9]+(\.|,)[0-9]+' | head -n 3 | sed -n 3p)
+    15)
-    fi
+      load_select=3
+      ;;
+  esac
 
+  case "$OS" in
+    OSX|BSD)
+      load_avg=$(sysctl vm.loadavg | grep -o -E '[0-9]+(\.|,)[0-9]+' | sed -n ${load_select}p)
       if [[ "$OS" == "OSX" ]]; then
         cores=$(sysctl -n hw.logicalcpu)
       else
         cores=$(sysctl -n hw.ncpu)
       fi
-  else
+      ;;
-    load_avg=$(grep -o "[0-9.]*" /proc/loadavg | head -n 1)
+    *)
+      load_avg=$(cut -d" " -f${load_select} /proc/loadavg)
       cores=$(nproc)
-  fi
+  esac
 
   # Replace comma
   load_avg=${load_avg//,/.}
 
   if [[ "$load_avg" -gt $(bc -l <<< "${cores} * 0.7") ]]; then
     current_state="critical"
-elif [[ "$load_avg" -gt $(bc -l <<< "${cores} * 0.5") ]]; then
+  elif [[ "$load_avg" -gt $(bc -l <<< "${cores} * 0.5") ]]; then
     current_state="warning"
   else
     current_state="normal"