powerpc: floppy: Add missing checks after DMA map

The DMA map functions can fail and should be tested for errors.

Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250620075602.12575-1-fourier.thomas@gmail.com

Author: Thomas-fourier

arch/powerpc/include/asm/floppy.h

@@ -144,9 +144,12 @@ static int hard_dma_setup(char *addr, unsigned long size, int mode, int io)
 		bus_addr = 0;
 	}
 
-	if (!bus_addr)	/* need to map it */
+	if (!bus_addr) {	/* need to map it */
 		bus_addr = dma_map_single(&isa_bridge_pcidev->dev, addr, size,
 					  dir);
+		if (dma_mapping_error(&isa_bridge_pcidev->dev, bus_addr))
+			return -ENOMEM;
+	}
 
 	/* remember this one as prev */
 	prev_addr = addr;