Fix multiple problems in -break-condition command.

1. To handle the expression with spaces, this command uses 2 arguments. For a case
   like -break-condition 1 i == 5, the first will pick the 'i' and second will
   pick the '== 5'. But the second argument was made mandatory which failed in
   cases when there was no space in the expression like i==5.
2. The function GetRestOfExpressionNotSurroundedInQuotes has 2 locals with the
   same names. It resulted in one hiding the other and this function always
   returned empty string.

No regression on Linux. Committed as obvious.

llvm-svn: 246847