ZynAddSubFX: fixed possible accesses beyond array boundaries

GCC issued a few warnings concerning array out-of-boundary accesses.
This commit fixes them.

plugins/zynaddsubfx/src/Misc/Bank.C

@@ -293,7 +293,7 @@ int Bank::newbank(const char *newbankdirname){
     if (((bankdir[strlen(bankdir)-1])!='/')&&((bankdir[strlen(bankdir)-1])!='\\')){
 	strncat(bankdir,"/",MAX_STRING_SIZE);
     };
-    strncat(bankdir,newbankdirname,MAX_STRING_SIZE);
+    strncat(bankdir,newbankdirname,MAX_STRING_SIZE-1);
 #ifdef OS_WINDOWS
     result=mkdir(bankdir);
 #else

plugins/zynaddsubfx/src/Misc/Part.h

@@ -138,7 +138,7 @@ class Part{
 
       EffectMgr *partefx[NUM_PART_EFX];//insertion part effects (they are part of the instrument) 
       unsigned char Pefxroute[NUM_PART_EFX];//how the effect's output is routed(to next effect/to out)
-      bool Pefxbypass[NUM_PART_EFX];//if the effects are bypassed
+      bool Pefxbypass[NUM_PART_EFX+1];//if the effects are bypassed
       
 
       pthread_mutex_t *mutex;