… declaration of abs function

with gcc-14 this warning becomes a failure

 90s /tmp/autopkgtest.g0L4Ek/autopkgtest_tmp/example_csscal.c: In function ‘main’:
 90s /tmp/autopkgtest.g0L4Ek/autopkgtest_tmp/example_csscal.c:67:26: error: implicit declaration of function ‘abs’ [-Wimplicit-function-declaration]
 90s    67 |     int lenX = 1 + (N-1)*abs(incx);
 90s       |                          ^~~
 90s /tmp/autopkgtest.g0L4Ek/autopkgtest_tmp/example_csscal.c:26:1: note: include ‘<stdlib.h>’ or provide a declaration of ‘abs’
 90s    25 | #include <clBLAS.h>
 90s   +++ |+#include <stdlib.h>
 90s    26 |
 90s /tmp/autopkgtest.g0L4Ek/autopkgtest_tmp/example_csscal.c:89:5: warning: ‘clCreateCommandQueue’ is deprecated [-Wdeprecated-declarations]
 90s    89 |     queue = clCreateCommandQueue(ctx, device, 0, &err);
 90s       |     ^~~~~