fix build bustage with 64 bit seekable streams

netwerk/base/src/nsFileStreams.cpp

@@ -365,7 +365,7 @@ nsFileInputStream::IsNonBlocking(PRBool *aNonBlocking)
 }
 
 NS_IMETHODIMP
-nsFileInputStream::Seek(PRInt32 aWhence, PRInt32 aOffset)
+nsFileInputStream::Seek(PRInt32 aWhence, PRInt64 aOffset)
 {
     if (!mFD) {
         if (mBehaviorFlags & REOPEN_ON_REWIND) {

netwerk/base/src/nsFileStreams.h

@@ -84,7 +84,7 @@ public:
     NS_DECL_NSILINEINPUTSTREAM
     
     // Overrided from nsFileStream
-    NS_IMETHOD Seek(PRInt32 aWhence, PRInt32 aOffset);
+    NS_IMETHOD Seek(PRInt32 aWhence, PRInt64 aOffset);
 
     nsFileInputStream() : nsFileStream() 
     {