shiny roll calc as separate function

include/wild_encounter.h

@@ -42,5 +42,6 @@ u16 GetLocalWaterMon(void);
 bool8 UpdateRepelCounter(void);
 bool8 TryDoDoubleWildBattle(void);
 bool8 StandardWildEncounter_Debug(void);
+u32 CalculateChainFishingShinyRolls(void);
 
 #endif // GUARD_WILD_ENCOUNTER_H

src/pokemon.c

@@ -1151,7 +1151,7 @@ void CreateBoxMon(struct BoxPokemon *boxMon, u16 species, u8 level, u8 fixedIV,
             if (LURE_STEP_COUNT != 0)
                 totalRerolls += 1;
             if (I_FISHING_CHAIN && gIsFishingEncounter)
-                totalRerolls += (2 * gChainFishingDexNavStreak);
+                totalRerolls += CalculateChainFishingShinyRolls();
 
             while (GET_SHINY_VALUE(value, personality) >= SHINY_ODDS && totalRerolls > 0)
             {

src/wild_encounter.c

@@ -869,6 +869,11 @@ bool8 DoesCurrentMapHaveFishingMons(void)
         return FALSE;
 }
 
+u32 CalculateChainFishingShinyRolls(void)
+{
+    return (2 * gChainFishingDexNavStreak);
+}
+
 static void UpdateChainFishingSpeciesAndStreak(u32 species)
 {
     if (!I_FISHING_CHAIN)