add doSizeControlledMalloc func to check the size of malloc.
FIXME: ktesttool will not generate the testcase correctly.

Signed-off-by: xqx <xqx@klee.(none)>
regularize the code style in Exprvisitor.h

Signed-off-by: xqx <xqx@klee.(none)>
regularize the code style in Exprvisitor.cpp

Signed-off-by: xqx <xqx@klee.(none)>
amend the doSizeContolledMalloc Func , it could check the size of malloc
correctly now. but an exception when the size is the complete arg of the
called func.

Signed-off-by: xqx <xqx@klee.(none)>