My apologies for this late reply.
Please can you try with library path as C:\Program Files (x86)\AMD APP SDK\2.9\lib\x86.
Your build settings may be set fro 32 bit app but you are trying to link the 64 bit OpenCL library. That's may be the reason.
I faced the same problem to build an OpenCL project using Eclipse by VSC++ tool chain. By default it was trying to build a 32 bit app but I linked the OpenCL.lib from C:\Program Files (x86)\AMD APP SDK\2.9\lib\x86_64 and got the error. When I modified the path as the following, it worked for me:
Library path (-L): C:\Program Files (x86)\AMD APP SDK\2.9\lib\x86
Library (-l): OpenCL.lib