lmbench: Fix setting LDLIBS failure
scripts/build is interpreted as an sh script which may not recognize variable
assignment operator += and thus give the following error and fail to append
LDLIBS.
../scripts/build: 21: ../scripts/build: LDLIBS+=-lm: not found
Use the basic assignment instead.
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>