Fix cp error when NAME != quich

[Mango0x45]

Compiling with sudo make install NAME=calc for example results in

gcc -o calc src/helper.c src/parser.c src/lexer.c src/variable.c src/quich.c -lm -std=c99 -pedantic -Wall -Wextra -Wmissing-prototypes -Wstrict-prototypes -Wold-style-definition
mkdir -p /usr/local/bin
cp quich /usr/local/bin/calc
cp: cannot stat 'quich': No such file or directory
make: *** [Makefile:16: install] Error 1

This fixes that

[Usbac]

Merged! Thank you 😄