BaseTools: Fix a Eot issue.

FirmwareVolume.UnDispatchedFfsDict is mutated during iteration,
convert the FirmwareVolume.UnDispatchedFfsDict.keys() to a new list
 to resolve this problem.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Bob Feng <bob.c.feng@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

BaseTools/Source/Python/Eot/EotMain.py

@@ -391,7 +391,7 @@ def Dispatch(self, Db=None):
         FfsDxeCoreGuid = None
         FfsPeiPrioriGuid = None
         FfsDxePrioriGuid = None
-        for FfsID in self.UnDispatchedFfsDict.keys():
+        for FfsID in list(self.UnDispatchedFfsDict.keys()):
             Ffs = self.UnDispatchedFfsDict[FfsID]
             if Ffs.Type == 0x03:
                 FfsSecCoreGuid = FfsID
@@ -497,7 +497,7 @@ def LoadPpi(self, Db, ModuleGuid):
     def DisPatchDxe(self, Db):
         IsInstalled = False
         ScheduleList = sdict()
-        for FfsID in self.UnDispatchedFfsDict.keys():
+        for FfsID in list(self.UnDispatchedFfsDict.keys()):
             CouldBeLoaded = False
             DepexString = ''
             FileDepex = None
@@ -562,7 +562,7 @@ def DisPatchDxe(self, Db):
 
     def DisPatchPei(self, Db):
         IsInstalled = False
-        for FfsID in self.UnDispatchedFfsDict.keys():
+        for FfsID in list(self.UnDispatchedFfsDict.keys()):
             CouldBeLoaded = True
             DepexString = ''
             FileDepex = None