modify msync code so that only base address is page-aligned (#6585)
modify msync code so that only base address is page-aligned (#6585)

according to man msync, there is no need for the end address to be page-aligned
also use uintptr_t consistently instead of intptr_t
fceller/arangodb,fceller/arangodb,graetzer/arangodb,graetzer/arangodb,wiltonlazary/arangodb,graetzer/arangodb,Simran-B/arangodb,graetzer/arangodb,graetzer/arangodb,wiltonlazary/arangodb,arangodb/arangodb,Simran-B/arangodb,wiltonlazary/arangodb,fceller/arangodb,graetzer/arangodb,fceller/arangodb,arangodb/arangodb,Simran-B/arangodb,fceller/arangodb,arangodb/arangodb,fceller/arangodb,graetzer/arangodb,graetzer/arangodb,wiltonlazary/arangodb,graetzer/arangodb,arangodb/arangodb,wiltonlazary/arangodb,Simran-B/arangodb,wiltonlazary/arangodb,arangodb/arangodb,fceller/arangodb,Simran-B/arangodb,graetzer/arangodb,Simran-B/arangodb,fceller/arangodb,fceller/arangodb,graetzer/arangodb,graetzer/arangodb,Simran-B/arangodb,arangodb/arangodb,arangodb/arangodb,Simran-B/arangodb,graetzer/arangodb,wiltonlazary/arangodb,arangodb/arangodb,wiltonlazary/arangodb,fceller/arangodb,Simran-B/arangodb,Simran-B/arangodb,graetzer/arangodb