Fix error message for 'incompatible operand' - added line number
Fix error message for 'incompatible operand' - added line number

Fixes bug 610414.

frida/vala,themiwi/vala,flobrosch/vala-fixes,Distrotech/vala,severinh/vala,tjol/vala-tjol,themiwi/vala,rvu95/vala,rvu95/vala,GNOME/vala,tjol/vala-tjol,spidermonkdust/vala,spidermonkdust/vala,severinh/vala,severinh/vala,tjol/vala-tjol,playya/vala,frida/vala,kamanashisroy/aroop,frida/vala,xdave/pvala,playya/vala,frida/vala,rvu95/vala,spidermonkdust/vala,themiwi/vala,kamanashisroy/aroop,frida/vala,playya/vala,GNOME/vala,kamanashisroy/aroop,flobrosch/vala-fixes,Distrotech/vala,jessevdk/vala,flobrosch/vala-fixes,Distrotech/vala,jessevdk/vala,GNOME/vala,jessevdk/vala,GNOME/vala