* fgrep can't be used with regex

Makefile

@@ -4,7 +4,7 @@ ARLIB := libi2pd.a
 SHLIB_CLIENT := libi2pdclient.so
 ARLIB_CLIENT := libi2pdclient.a
 I2PD  := i2pd
-GREP := fgrep
+GREP := grep
 DEPS := obj/make.dep
 
 include filelist.mk

Makefile.linux

@@ -55,7 +55,7 @@ IS_64 := $(shell $(CXX) -dumpmachine 2>&1 | $(GREP) -c "64")
 ifeq ($(USE_AESNI),yes)
 ifeq ($(IS_64),1)
 #check if AES-NI is supported by CPU
-ifneq ($(shell grep -c aes /proc/cpuinfo),0)
+ifneq ($(shell $(GREP) -c aes /proc/cpuinfo),0)
 	CPU_FLAGS = -maes -DAESNI
 endif
 endif